Revision as of 09:59, 8 January 2009

Introduction

This page is about the Zoom Slider in Writer (OOo 3.0). The general Zoom function is not discussed here, but only the implementation of the GUI element and how it could be enhanced for a better user experience.

The zoom value indicator is understood as a part of the Zoom Slider, here.

Issues with the Zoom Slider

Usability issues

• It is hard to use for people with disabilities (as most sliders).
• Clicking on the slider's slit to set a zoom value is hazardous: since there is no feedback and the (unlabeled) scale is non-linear, the user can't know the value that will be set when clicking.
• There is a snapping of the handle near the predefined values, but the snapping area is very small, so it may be difficult to reach for some users, and according to Fitt's Law, it takes some (too much?) time.
• It is impossible to escape the snapping, so a value close to a predefined one can't be selected with the slider.

Design and User Experience issues

• It is located in the status bar, a place supposed to be underlooked by users, if not totally ignored.
• Some options of the “View > Zoom…” dialog can not be set with the slider by dragging the handle: "Optimal", "Adapt to width" and "Other", the last one needing an additional value (see issue 68625 and issue 50134.)
• These predefined values can not be added to the current design because of the proximity of the corresponding marks.
• The zoom value indicator can be right-clicked (for a drop-down menu of predefined values) or double-clicked (to open the “View > Zoom…” dialog), but there is no hint about this, so users don't know it (see issue 5182.)

Does not follow usual guidelines

• No visual change upon mouse over or click to suggest affordances and/or show feedback.
• No tooltip.
• No label on predefined values.
• -/+ Buttons are always highlighted (in blue).
• The zoom value indicator is visually separated from the controller changing its value (the slider).
• The zoom value indicator is enclosed in an area with an inset-style border suggesting that it is an editable text field while it is not.
• The slider is not sensitive to mouse-wheel input (see issue 88565.)

Small visual details

• The -/+ buttons are vertically misaligned with the slider's slit. One pixel down would be better :)
• The handle has an even size in pixels so it can't be correctly centered.
• The zoom value indicator is partially covered by the window resizing handle, in Mac OS X (and probably many window managers for XWindow.) The position of the Zoom Slider creates another issue when resizing the window with a width smaller than 1024 pixels (see issue 94061.)

Mockups and proposals

Clément Pillias has made a proposition to enhance the Zoom Slider, called the “Gear Stick Metaphor”. It provides the same functionality as a menu, while preserving the "instantaneous preview" behavior of the slider, and allow to change the selected value by only moving the mouse. Moreover, the position of the mouse selecting a particular option is easy to learn (similar to a pie menu), and the whole thing has an expert mode (no need to even look at the slider). Mockups are being made.

To be completed…